.container {
    max-width: 960px;
}
@media (min-width: 1200px)
.container {
    max-width: 1140px;
}
@media (min-width: 992px)
.container {
    max-width: 960px;
}
@media (min-width: 768px)
.container {
    max-width: 720px;
}
@media (min-width: 576px)
.container {
    max-width: 540px;
}
.container {
    width: 100%;
    padding-right: 15px;
    padding-left: 15px;
    margin-right: auto;
    margin-left: auto;
}
*, ::after, ::before {
    box-sizing: border-box;
}
user agent stylesheet
div {
    display: block;
}
body {
    margin: 0;
    font-family: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol";
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.5;
    color: #212529;
    text-align: left;
    background-color: #fff;
}
:root {
    --blue: #007bff;
    --indigo: #6610f2;
    --purple: #6f42c1;
    --pink: #e83e8c;
    --red: #dc3545;
    --orange: #fd7e14;
    --yellow: #ffc107;
    --green: #28a745;
    --teal: #20c997;
    --cyan: #17a2b8;
    --white: #fff;
    --gray: #6c757d;
    --gray-dark: #343a40;
    --primary: #007bff;
    --secondary: #6c757d;
    --success: #28a745;
    --info: #17a2b8;
    --warning: #ffc107;
    --danger: #dc3545;
    --light: #f8f9fa;
    --dark: #343a40;
    --breakpoint-xs: 0;
    --breakpoint-sm: 576px;
    --breakpoint-md: 768px;
    --breakpoint-lg: 992px;
    --breakpoint-xl: 1200px;
    --font-family-sans-serif: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol";
    --font-family-monospace: SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace;
}
html {
    font-family: sans-serif;
    line-height: 1.15;
    -webkit-text-size-adjust: 100%;
    -ms-text-size-adjust: 100%;
    -ms-overflow-style: scrollbar;
    -webkit-tap-highlight-color: transparent;
}
user agent stylesheet
html {
    color: -internal-root-color;
}
*, ::after, ::before {
    box-sizing: border-box;
}
*, ::after, ::before {
    box-sizing: border-box;
}